DORAL, Fla. (AP) - No disease-carrying mosquitoes have been found so far this year in the Miami area, but officials are prepared to launch aerial pesticide spraying to stamp out any reemergence of Zika, according to the head of mosquito control in the first U.S. county to report transmission of the virus linked to severe birth defects.
Miami-Dade County Mosquito Control Operations Manager Chalmers Vasquez also said Monday at a municipal workshop that aggressive code enforcement was essential to eliminating mosquito breeding sites because, despite millions of dollars spent on public outreach, residents and business owners often failed to drain standing water from their properties.
While active transmission zones were identified only in Miami and Miami Beach, about 460 Zika infections were reported by travelers and Miami-Dade residents outside those areas, Vasquez said.
"This was all over the county," he said.
In four neighborhoods where local mosquitoes spread the virus, trucks continue to spray pesticides targeting mosquito larvae. The county shifted these preventative treatments - bacteria toxic only to mosquito larvae - from planes to trucks last summer because of public opposition to any aerial pesticide spraying, Vasquez said.
However, he credited dramatic drops in the numbers of Zika-carrying mosquitoes to aerial applications of naled, a pesticide used since the 1950s in the U.S. to kill adult mosquitoes.
Vasquez said he'd recommend aerial spraying if faced with another public health emergency.
"This is how we broke the cycle of transmission," he said.
Mayor Carlos Gimenez pledged to continue aggressive mosquito control measures, noting that Brazil is struggling with an outbreak of yellow fever - another mosquito-borne virus.
"We don't want any other diseases to make their way up here," he said.
Miami-Dade County now screens mosquitoes for Zika, dengue fever and chikungunya as part of an enhanced surveillance network, Vasquez said. New pesticides also are being used, after testing showed mosquitoes were resistant to chemicals the county had been using.
Water collecting at construction sites and in the leaves of bromeliads remains a major concern. The county has been removing bromeliads from public property, said Paul Mauriello, deputy director of the Miami-Dade County Department of Solid Waste Management.
Zika mainly spreads by mosquito bites but also can spread through sex. People can be infected without showing symptoms, and the virus can remain in semen for months.
U.S. health officials still caution pregnant women to postpone travel to Miami-Dade County.